As home network protocols, there are a universal plug and play (UPnP) technology and a digital living network alliance (DLNA) technology.
The UPnP technology and the DLNA technology enable the service and control between consumer electronics of various manufacturers. In particular, the UPnP technology enables the compatible audio/visual (AV) service and control between pieces of AV equipment. The compatible AV service includes media streaming, uploading, downloading, etc.
The DLNA regulates a digital media server (DMA), a digital media player (DMP), a digital media renderer (DMR), a digital media controller (DMC), and a digital media printer (DMPr) as a home network device, and regulates a mobile digital media server (M-DMS), a mobile digital media player (M-DMP), a mobile digital media uploader, (M-DMU), a mobile digital media downloader (M-DMD), and a mobile digital media controller (M-DMC) as a mobile portable device.
The digital media server (DMS) is used as an idea of covering the M-DMS, the digital media player (DMP) is used as an idea of covering the M-DMP, and the digital media controller (DMC) is used as an idea of covering the M-DMC.
The UPnP classifies such devices into a control point (CP) device and a control target device. The digital media controller (DMC) and the digital media player (DMP) are classified as the control point device, and the digital media renderer (DMR), the digital media server (DMS), and the digital media printer (DMPr) may be classified as the control target device.
The LDNA defines a two box model and a three box model.
The two box model includes the digital media player (DMP) and the digital media server (DMS). In the case of the two box model, the digital media player (DMP) allows a user to find and play content that is browsed and distributed by the digital media server (DMS).
The three box model includes the digital media controller (DMC), the digital media server (DMS), and the digital media renderer (DMR). In the case of the three box model, the digital media controller (DMC) allows the user to find the DMS's content to be played by the digital media renderer (DMR).
Equipment conforming to the UPnP and the DLNA gives and receives commands through internet protocol networking (IP networking). That is, one of connected pieces of AV equipment may provide an AV service to another piece of equipment, receive an AV service from another piece of equipment, control another piece of equipment, and be controlled by another piece of equipment.
However, there is a limitation in that the resource usage state (for example, a state during a service) of a power device supporting a low power mode (for example, digital media server (DMS)) in order to prevent power consumption and states of various physical or logical devices of equipment are not considered typically. That is, when a power device that is using a resource receives from a power control device a request for changing to a low power state, an existing service stops and thus a user who is using the power device may experience inconvenience.
In addition, when the power device that is using the resource rejects the request from the power control device for changing to the low power state, there is a limitation in that the power control device determines that there is an error in the power device or the power control device because the power control device does not know why the request is rejected.
In addition, since existing equipment conforming to the UPnP and the DLNA may change a power state by an external request and may not change parameters for changing the power state due to an internal factor, it may be difficult to dynamically respond to external requests.